Envelop.



G. M. J. AHL'STROM.

ENVELOP. APIfLIOATION FILED MAYZ, 1908 'Patented Feb. 9, 1909.

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' disposed flaps that 'UNTTED sTATEs Gos'rA'M. J'. AHLs'rnoM, 4 or rrr'isiann'e, PENNSYLVANIA.

PATENT onirica.

v Envnnor.

Specification of Letters Patent.

Patented Feb. 9, 1909'.

To all whom it may concern:

Be it known that I, Gos'rA' M J. AHL- srnoM, a citizen of the United Stat-e5, reSiding at Pittsburg, in the countyl of Alleglieny and State ofI Pennsylvania,.have invented -new and useful Improvements in Envelops, of which the following is a specification. This invention relates to venvelope and more particularly to those of the safety' type designed to prevent surreptitious opening of the envelop without danger ofdetection.

. The invention'has for one of its objects to improve and simplify the construction of envelope of this character so as to be coni,-

easy and inexpensive to manu.

aratively acture, readily sealed, and comparatively safe against tampering with.

Another object of the invention is the provision of the envelop having oppositelyare provided with approximately semi-circular slits of diiferent radii to form tabs, the tab on one iap being inserted under the other flap and sealed thereto, while the tab of the second tab is sealed to the outside of the first Hap.

With these objects in view and others, as will. appear as the description proceeds, the

invention comprises the various novel fea-. tures of construction vand arrangement of parts which will be more fully `described hereinafter and-set--forth with particularity in the claims appended hereto.

In' the accompanying drawing, which illustrates one embodiment of the invention, Figure 1 is a rear elevation ofthe sealed envelop. Fig. 2 is a similar view with the sealing flap open. Fig. 3 is a plan view`of the enlvelop blank.

Y Similar reference characters are employed to designate corresponding parts throughout the several views.

Referring lto the drawing, A designates the blank of the envelop whic in the present instance,i comprises'a body 1,A end iaps f 2 and 3, and,` top and bottom flaps 4' and 5,

` the flaps being folded on the creases 6. The

bottom flap has ai semi-circular slit 7 the vcenter of which lisflocated in a linepassing centrally' throughtlie tia and the slit is dis- 4 posed inwardly a suitable distance from the edge 8 'of the flap so thatJ the marginal por-l tion of the latter can b. Vsuppliedlwith adhesive 9. The slit 7 thus fo'rnisjt tab 10, the

, of tlie'endilaps by fold 6 betweenthe bottom iiap 5 and body l. Attd the' 'ends of the base line are laterallyextending' slits-'112 for-the purpose hereinafter to appear, the inner surface of the tab 10 being provided with adhesive, .as shown in Fig. 3. The top iiap 4 has a slit 13 which is. slightly larger than a semi-circle and is arranged on a center line of the said flap. The inner surface o f the top fiap has portion thereof and between the sli't 13 andv free edge 15,v and the inner surface of the' tab. 16is also supplied with adhesive. The tab is slit inwardly at 17 in line with the vbase thereof and the corners 18 of the tab are adapted to engage with the slits 12 when the envelop is sealed. The distance stantially the same as the dimension of the tab 16 at its widest point. After the blankv is made, completed by folding the iiaps on the ineS 6, the flaps 2 and''being first glued to ether by adhesive on one -or the other an' then -the bottom iiap sealed to the outside surfaces the adhesive 9, the 'tab '1.0 being left free, thus producing an envelopas shown in Fig. 2 In finally sealing the enyelop after the contents have been placed therein, the top iiap is folded down over the back of the envelop after first and this'lnoistened tab is inserted in the slot 7 of the bottom flap and forced inwardly under the latter flap. The gumined portion 16 of the top flap is next moistencd and stuck to 'the outside of the bottom iiap, after which side of the top flap, as shown' in Fig. 1. By this means, the top flap is glued to 'the bottom flap' in the usual manner and the tab on the bottoni iiap glued to the top flap, while the large flap is glued to 'the outer faces of the end flaps. It will thus be seen that the parts are ai'nply stuck to each other tcction is practically impossible.

Having thus described the invention, what I claim is oppositely-disposed iiaps, one flap having anl extending slit-s at thev endsof the arcuate .t Sia and in une with the bas gf the ab, are" arcuate slit ifgrrning a tab and outwardly-- base ln'efllv of which i s parallel with the l 'adhesive 14 extending around the marginal between the outer ends'of the slits 12 is subtheenvelo `llis moistening the adhesive on the large tab 16,

the tab 10 is nioistened and stuck to the vouta so that opening of theenvelop without de- 105 1. An envelop comprising a blank having v 

